The present invention relates to a radiation analyzer.
An energy-dispersive X-ray detector that may be provided to a scanning electron microscope (SEM), an X-ray microanalyzer (XMA), or the like is normally secured through a flange (i.e., interface) corresponding to one working distance and one X-ray take-off angle specified by the specification.
JP-A-8-222172 and JP-A-9-147781 disclose an electron microscope that includes a plurality of energy-dispersive X-ray detectors so that two or more different X-ray take-off angles can be used.
In recent years, the working distance specified by the specification has been reduced along with an increase in resolution of a scanning electron microscope. When the working distance is short, X-rays may be interrupted (blocked) by a pole piece when detecting X-rays using the X-ray detector (i.e., it may be difficult to detect X-rays). It may be possible to prevent such a situation by reducing the X-ray take-off angle so that the X-ray detector can be used at a short working distance, for example. In this case, however, the X-ray detection accuracy may deteriorate when measuring X-rays at a long working distance.
A plurality of X-ray detectors may be provided to a scanning electron microscope so that an X-ray detector that detects X-rays at a low X-ray take-off angle is used when the working distance is short, and an X-ray detector that detects X-rays at a high X-ray take-off angle is used when the working distance is long. Specifically, X-rays may be measured using a plurality of X-ray detectors at an optimum X-ray take-off angle that corresponds to the working distance. In this case, however, an increase in cost and size of the device may occur since a plurality of X-ray detectors are necessary.